Athens, Temple of Olympian Zeus and The Arch of Hadrian

I am putting both of these ancient sights together because they were built so close together and they were finished by the Roman Emperor Hadrian, he admired Greece greatly and wanted Athens to be the cultural capital of the Roman Empire.

Ruins of the Temple of Olympian Zeus

The Temple sits on top of another ancient sanctuary dedicated to Zeus, after it's destruction 2 sons started to build one of the largest temples in Antiquity in 520BC, but with the fall of their tyranny and the advent of Athenian Democracy the building stopped and was left unfinished for 336 years.  Then a crazy Seleucid King who thought he was the earthly embodiment of Zeus restarted the works with a new architectural plan in 174BC, work stopped at his death in 164 BC, it was half completed.  It was finally completed by Emperor Hadrian in 132 AD, some 300 years later, taking over 600 years to complete, talk about a big UFO (for my sewing buddies). It was badly damaged and sacked in 267 and was never rebuilt.  The ruins are massive and if you use a little imagination you can just picture how big this Temple would have been.  In the picture above you can see the Acropolis in the background.

Arch of Hadrian, just outside the iron fence of the Temple of Zeus

This is right on a major road, Amalias Avenue, it is like a Roman Triumphal Arch and is dedicated to Hadrian by the Athenian Panhellenes, built around the same time that the Temple of Zeus was finished around 132AD.
All of the major sights of Athens are within easy walking distance to each other, especially if you are staying in Plaka or Monastiraki areas, or just down from Syntagma metro station.  The entrance fee for the Acropolis can also get you into the Temple, you can get this ticket at the front gate to the Temple if you go there first.